David Kellog Lewis (1941-2001) was an American philosopher, one of the most influential of his generation and, in perspective, one of the most systematic. His philosophy rests on two main theoretical beliefs. According to one, truths about natural facts, truths about intentional facts and mental states, and truths about normative facts (social conventions and ethical norms) all supervene upon the distribution of local qualities. According to the other belief, supervenience rests solely on intrinsic properties: that is to say, local qualities are all intrinsic. This article offers a panoramic view of the philosophical production of David Lewis, which starts from the local qualities comprising the supervenience basis and moves upwards. David Kellog Lewis era un filosofo americano, uno dei più influenti della sua generazione e, in prospettiva, tra i più sistematici mai nati oltreoceano. La sua produzione filosofica consta di quattro monografie e di circa cento articoli (ottantanove dei quali sono raccolti in cinque volumi pubblicati tra il 1983 e il 2000), e si distingue per lo stile chiaro, conciso e calzante.
